understanding high pressure versus low pressure propane

[adamant]

Thanks for the tip. You obviously know what your talking about where as this is like learning a new language for me.

Which of the vr8200 valves on this page would be best?

Why do they all say they are regulated to 3.5"wc? I was planing on using propane at 11"wc. Will that be a problem?

How does this standing pilot systems compare with the intermittent pilot and the hot surface ignition? Seams like standing pilot is the cheapest of the three. If there a reason to spend more for one of the other systems? Safety?

Thanks for your help!

What happens if the pilot light blows out?

 

[maida7]

What happens if the pilot light blows out?

It's my understanding that there is a sensor at the pilot light and if the pilot is not lit the valves will not open.

 

[adamant]

It's my understanding that there is a sensor at the pilot light and if the pilot is not lit the valves will not open.

Do those require a separate pilot assembly, or is it included as part of the valve?

 

[maida7]

Do those require a separate pilot assembly, or is it included as part of the valve?

Yes and a thermocouple. Look at post #7 in this thread for what's needed.

 

[adamant]

Yes and a thermocouple. Look at post #7 in this thread for what's needed.

Awesome, thanks.

 

[adamant]

Yes and a thermocouple. Look at post #7 in this thread for what's needed.

Is there any other difference between the 8200 and 8300 other than outlet size? Nevermind, I see this addressed above, now.

Looking at 2NobleDog's rig on the first page of the thread, he has 2 2-stage regulators coming from his manifold. Is that necessary, or could 1 regulator coming off the tank work also? That was the impression I got from Kladue's note about my rig being able to switch between fuels.

 

[kladue]

With the 10" burners running at a nominal 80,000 btu's LP, 65,000 btu's NG the VR8200 valve from honeywell is more than adequate for both fuels. Once it was setup for the higher pressure propane operation you can switch to NG without having to touch the gas valve pilot spring as it will be wide open on NG. The pilot burner will not burn high enough to work reliably on NG without switching the orifice inside the gas connection to the pilot ( .010" for LP, .018 for NG). If you leave the NG orifice in the pilot it will burn dirty on LP and the thermocouple will carbon up and probably shut down after 30-45 minutes as carbon would reduce flame heat transfer to a point the safety valve will close. After cleaning the carbon buildup off the thermocouple will continue working but a clean blue pilot flame is what is needed for reliable operation.
Pilot burner orifice and the burner gas jet swap should be all that is needed to swap fuels and with most pilot burners sold they include both orifices in the bag of parts. This usually involves 1 - 1/2" and 2 -7/16 wrenches, and a couple minutes to unscrew the 1/4" gas line nut, the body fitting just above, swap the orifice, and re-assemble.
The pilot flame heats a power generating thermocouple which holds a internal safety valve open inside the honeywell valve. If the pilot goes out the power generated by the thermocouple to hold the safety valve open goes away and the valve closes to prevent gas flow.
That is the reason you have to hold the pilot gas button down for about 30 seconds after the pilot lights up to let the power build up to a point it will hold the safety valve open when you release the pilot gas button.
The pilot needs to be attached to the side of the burner so the flame which leaves at about a 45 degree angle will just miss the burner casting and pass over one of the burner openings. Usually that means about 1/2" away from burner casting ,and top of the pilot flame diffuser about equal to the burner top.

 

[adamant]

I would do a search for 2 stage propane regulators and skip the one you linked, they should be much cheaper and available from a RV parts supplier or Lowes.
As to the pipe manifold, 1/2" iron pipe is sufficient for both NG and LP propane as the 10" burners will output 65K+ on NG and 80K on propane, both ratings within the normal pressure drop range for the short pipe manifold you will build.
When using the 10" burners without automatic valves, changing the burner gas jet will cost about $7 each for a NG orifice valve http://www.brewershardware.com/Valve-and-NG-Orifice-for-BURN10-BURNVALVENAT.html, and the same for a propane valve http://www.brewershardware.com/Valve-and-LPG-Orifice-for-BURN10.html. It will take about 5 minutes to switch valves/orifices when fuel switching, and a colored ty-wrap or paint coating on the valve will help identify the fuel they were built for to save confusion later.
When using the honeywell furnace valves you need to remove the outer screw cap for the internal regulator, spring retainer, and spring to swap springs to make the fuel switch as the operating pressure ranges are different, 4-6" Wc for NG (1/6 Psi - silver spring), 11-13" Wc for propane (1/2 Psi - red spring).

Any idea how different the orifice sizes are on those valves that you linked?

 

[kladue]

The LP valves have a nominal 3/32" opening, and the NG valves have a larger nominal 1/8" opening.

 

[adamant]

The LP valves have a nominal 3/32" opening, and the NG valves have a larger nominal 1/8" opening.

hmm, how much performance reduction is there if you used LP with an NG orifice or NG with an LP orifice?

 

[kladue]

For the LP using NG orifice you get orange flames and soot, with NG using LP orifice you get 1/4" high flames. The fuel pressure has a big influence over the amount of primary air drawn into the burner, lower pressure means lower air flow and lower output. For the traditional 15 -3/4" keg and a 16" pot the highest btu input under the keg or pot is about 80,000 btu's. You can push more fire under the pot, but the amount over 80,000 btu input is just the flames up the sides which do not contribute heating effort, and just destroy all the flame vulnerable bits and pieces on the sides.
Having a 200,000+ btu burner sounds cool and one would expect faster heating, but practical experience gained from many builds over the last decade have shown that the burners had to be throttled back considerably ( down to 80,000 range ) to get the job done without destroying all the sight glasses and thermometers sticking out the sides of the pot.

 

[adamant]

Thanks. I appreciate the insight. It would be cool if there were adjustable orifices, but swapping out a $7 part is pretty reasonable.

 

[kladue]

It would be nice if someone could machine a stepped needle for the gas jet for the burner, turn it in for propane, out for NG, in a right angle valve body with 3/8" flare connection.

 

[Glot]

Wouldn't higher reg out pressure just increase the gas flow through the injector? Why not just increase the size of the injector and use a low pressure out reg?

 

[Glot]

Also, the Mj/h rating is how much gas it consumes. Different types of burners are more or less efficient at actually transferring that heat to the pot due to an effect know as the barrier layer.

 

[doublehaul]

why does everyone convert the BG14 to low pressure instead of just buying a low pressure burner like this:

http://www.agrisupply.com/low-pressure-burner-cast-iron-70000-btus/p/40282/

would this burner work well? are there others that are a good value like this that would work better?

 

[SafariJack]

Because it smaller? Or because the valve that you get from Williams brewing to convert to natural gas is specifically calibrated to the BG14? I'm not really sure to be honest, I'm just building mine with what seems to be the most common so that if a problem ever arises I should be able to get help on it


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[doublehaul]

Because it smaller? Or because the valve that you get from Williams brewing to convert to natural gas is specifically calibrated to the BG14? I'm not really sure to be honest, I'm just building mine with what seems to be the most common so that if a problem ever arises I should be able to get help on it


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I guess im asking why buy a burner you have to buy a conversion valve from Williams for rather than just buying a burner designed for low pressure to begin with. I get the size but it just seemed simpler to buy a LP burner to begin with, so I was just curious. I am planning my setup.

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[day_trippr]

why does everyone convert the BG14 to low pressure instead of just buying a low pressure burner like this:

http://www.agrisupply.com/low-pressure-burner-cast-iron-70000-btus/p/40282/

would this burner work well? are there others that are a good value like this that would work better?

The linked page says that burner is not for use with natural gas.
That might be one reason...

Cheers!

 

[doublehaul]

The linked page says that burner is not for use with natural gas.
That might be one reason...

I'm not looking to use natural gas, i am going to use propane... Not sure where the natural gas came from?

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[kladue]

The 6" btu rating was developed using high pressure propane, when used with low pressure the btu rating is more like 40,000. The low pressure route lets you use the Honeywell VR8200 gas valves for automated control. Optimum setups have been 10" for HLT and boil, and the 6" for direct fired mash tuns.

 

[ianw58]

why does everyone convert the BG14 to low pressure instead of just buying a low pressure burner like this:

http://www.agrisupply.com/low-pressure-burner-cast-iron-70000-btus/p/40282/

would this burner work well? are there others that are a good value like this that would work better?

That's the burner I have installed under my boil kettle. I'm very pleased with it.

 

[kirbcheck]

I think I read somewhere that for 10 gallon batches the 6" banjo wasn't cutting it... I'm just in the middle of building my brew stand, I can't remember which thread it was, but I'm sure I read it somewhere.

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[doublehaul]

I think I read somewhere that for 10 gallon batches the 6" banjo wasn't cutting it... I'm just in the middle of building my brew stand, I can't remember which thread it was, but I'm sure I read it somewhere.

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good to know

 

[ianw58]

I think I read somewhere that for 10 gallon batches the 6" banjo wasn't cutting it... I'm just in the middle of building my brew stand, I can't remember which thread it was, but I'm sure I read it somewhere.

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Crap! I better rethink this, then... BTW just took a first for my Porter brewed on this rig that doesn't work...

 

[kirbcheck]

Glad to hear it. I'm just repeating what I've read online. Can I ask how long it takes to bring 10+ gallons to a boil?

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[B4brew]

why does everyone convert the BG14 to low pressure instead of just buying a low pressure burner like this:

http://www.agrisupply.com/low-pressure-burner-cast-iron-70000-btus/p/40282/

would this burner work well? are there others that are a good value like this that would work better?

I went with the BJ14 burner because I felt the flame was evenly distributed on converted keg.

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[doublehaul]

I have been reading all related threads on this, but can't seem to find an answer to my specific question. I want to build a single tier, herms system with 2 burners. I want to automate only the HLT/herms burner.

The closest thread I found was this - https://www.homebrewtalk.com/f11/2-stage-low-pressure-propane-regulator-157661/#post1866776

This seems like it would be a good setup (except I wouldn't have the middle burner). Burner model asside, wouldn't it be an advantage to have the BK high pressure and the MLT low pressure? Is all that it would take is 2 regulators as shown in this thread? Is there any reason to opt for all low pressure over this setup? How big a difference in boil time do you think it would be have High vs. Low pressure BK? Thanks

 

[kladue]

The smart way to do the boil is to light up the burner at a lower flame level while transferring wort to the boil kettle, usually a 30+ minute process. By the time all the wort is in the boil kettle you are almost at a boil, if not already boiling. The higher output that high pressure would bring is negated by the throttling down of the burner to get a smaller fire during wort transfer and sparging.
Low pressure burners work well when used this way, fired up when 2" of wort is in boil kettle, and left at a lower fire until end of sparging.

 

[doublehaul]

The smart way to do the boil is to light up the burner at a lower flame level while transferring wort to the boil kettle, usually a 30+ minute process. By the time all the wort is in the boil kettle you are almost at a boil, if not already boiling. The higher output that high pressure would bring is negated by the throttling down of the burner to get a smaller fire during wort transfer and sparging.
Low pressure burners work well when used this way, fired up when 2" of wort is in boil kettle, and left at a lower fire until end of sparging.

Good point, I do that today (but have to cut my high pressure burner to avoid boil before all the wort is there) and that would probably work. I batch sparge, but that shouldn't matter. How about heating the strike water to temp for big batches - does that take a long time with a low pressure burner?